This invention relates to an improved manifold useful in washing or flushing the reaction channels in an apparatus used in laboratories for screening certain types of solutions. The improved manifold relates to the type of apparatus disclosed in my prior application for U.S. Pat. Ser. No. 07/011,291, now U.S. Pat. No. 4,834,946, filed Feb. 5, 1987, for "An Apparatus For Blot Screening Numerous, Small Volume, Antibody Solutions." A similar type of apparatus is also disclosed in my prior U.S. Pat. No. 4,713,349, issued Dec. 15, 1987, for a "Template For Simultaneously Screening of Several Antibodies and Method of Using the Same."
A known method, which is used to screen samples of different antibody solutions by the Western Blotting procedure, generally involves reacting the test solutions with proteins or antigens which have been immobilized on a transfer membrane. Visually observable markings, resulting from the reactions, appear on the membrane. These markings can be used for a screening analysis. To facilitate the procedure, and to reduce the time required for this type of analysis, microliter-size samples of different test solutions are introduced into channels in a plate for simultaneous contact with different parts of a treated transfer membrane. After reactions occur, it is necessary to flush the channels in order to rinse unbonded or unreacted materials therefrom. Also, for some tests it may be necessary to apply a single reactive fluid into all of the channels at about the same time. Initially, the channels are loaded individually or in small groups with the small samples for testing. Thus, there is a need for means for introducing and removing a single fluid, either for rinse or reaction purposes, simultaneously through all of the channels, while still permitting loading each channel separately.
By way of further background, the Western Blot procedure with which this apparatus is primarily concerned utilizes a thin membrane having bands of protein that were applied and separated through a gel electrophoresis procedure. During the blot procedure, the membrane is incubated with a primary antibody. Following incubation, unbound portions of the primary antibody are washed away. Then, the membrane may be incubated with a secondary or tracer antibody which is subjected to a washing step for removing unbound secondary antibody materials. Lastly, the membrane may be incubated with a color-generating substrate to produce visually observable antibody sites in the form of color bands or markings. These are used to determine analysis results.
The membranes utilized are commonly made of paper-like nitrocellulose sheets which carry proteins that have been electroblotted from polyacrylamide gels. The gels can include a single sample that is electrophoresed across the entire gel for use for screening a number of antibodies against the same antigen pattern. Alternatively, antibodies may be screened against different antigens electrophoresed in separate vertical lanes on the same gel.
In this type of screening, a relatively large number of separate rows or stripes of the sample solutions under assay are applied upon a single transfer membrane to produce side-by-side observable readings of the test results. The transfer membranes have a relatively large number of different bands of immobilized antigens located along the length of the membranes. Thus, the stripes of antibody solutions are applied transversely to the numerous bands. Observable test results occur at various locations along the lengths of the stripes where they intersect with the different bands. This provides the side-by-side comparisons of antibody blotting profiles.
This laboratory screening procedure may be conducted with an apparatus such as that disclosed in my above-mentioned application. That apparatus utilizes a test plate having a surface in which a large number of shallow, narrow, elongated channels are formed. The surface is applied against the test membrane, with the channels arranged transversely of the bands formed on the membrane. Test solution materials are introduced in each of the channels for contact with different parts of the single membrane. Since a large number of tests are conducted at the same time and with the same membrane, this procedure considerably reduces the overall time and expense needed for conducting such tests.
The apparatus described in my prior application includes a device which enables simultaneous introduction of a single fluid, such as a water rinse, through all of the channels. Although effective, it is desirable to provide a simpler device, which can be more rapidly applied and removed, so as to further reduce the amount of time and effort needed to conduct this laboratory testing procedure.